Optically Coherent Nitrogen-Vacancy Centers in Micrometer-Thin Etched Diamond Membranes

Area of Science:

• Quantum Optics
• Materials Science
• Nanotechnology

Background:

• Optically coherent nitrogen-vacancy (NV) centers in diamond are essential for quantum technologies.
• Novel cryogenic experiments and quantum networks require advanced diamond devices.

Purpose of the Study:

• To fabricate thin, smooth diamond membranes with individually resolvable, narrow linewidth NV centers.
• To optimize fabrication processes for high-quality diamond membranes for quantum applications.

Main Methods:

• Fabrication involved high-energy electron irradiation and high-temperature annealing.
• An optimized etching sequence was developed through systematic surface evolution studies.
• Diamond membranes with a thickness of (3.4 ± 0.2) μm and low surface roughness (r_q < 0.4 nm) were produced.

Main Results:

• Individually resolvable NV centers with narrow linewidths (< 100 MHz) were successfully integrated into the diamond membranes.
• The fabrication process yielded highly smooth surfaces, crucial for device performance.
• The resulting devices are suitable for cavity-enhanced entanglement generation.

Conclusions:

• The developed fabrication method produces high-quality diamond membranes with NV centers for quantum applications.
• These membranes are promising for optical ground-state cooling and quantum network development.
• The results advance the integration of quantum emitters with micrometer-scale device geometries.